Fluid pressure brake apparatus



Dec. 1, 1953 E. P. SEXTON FLUID PRESSURE BRAKE APPARATUS 2 Sheets-Sheet1 Filed Aug. 22, 1950 JNVENTOR. Everett RSexton A T TORNE Y Dec. 1, 1953E. P. SEXTON FLUID PRESSURE BRAKE APPARATUS 2 Sheets-Sheet 2 Filed Aug.22, 1950 OW 0m NW W0. Om 0N mm 095mm 0 mwwflwm TucwgwEm Q04 or ut m m mrINVENTOR. Everett P. S'exion llzm A T TORNE Y Patented Dec. 1, 1953FLUID PRESSURE BRAKE APPARATUS Everett P. Sexton, East McKeesport, Pa.,as-

signor to Westinghouse Air Brake Company, a corporation of PennsylvaniaApplication August 22, 1950, Serial No. 180,748

3 Claims. (Cl. 30318) This invention relates to fluid pressure brakeequipment and more particularly to the electropneumatic type for use inconnection with braking vehicles adapted to be controlled from eitherend and to be operated individually or in trains, such as subway cars orthe like.

Certain vehicles in the above type of service have for years beenequipped with Westinghouse Air Brake C'ompanys Amue Electro-PneumaticBrake equipment fully disclosed in their Instruction Pamphlet No.T-5051-13 dated February 1938. This equipment comprises two strip valvedevices located at opposite sides of the vehicle, one on each truck, insuch a manner that when a road bed trip is set against train movement,said trip will engage a normally depending handle of one of the tripvalve devices and operate said device to an open position for effectingan emergency reduction in pressure in the usual brake pipe to therebycause an emergency application of brakes on the vehicle or train, as thecase may be, to promptly bring it to a stop. A trip valve deviceapplication of brakes usually occurs, as just described, when theoperators brake valve device is in release position supplying fluidunder pressure to the brake pipe. It is undesirable to thus continuesupply of fluid under pressure to the brake pipe which is open toatmosphere through the operated trip valve device, so it is customary topromptly move the brake valve device to lap position to cut off thesupply of fluid under pressure to the brake pipe when such anapplication of brakes occurs. Before the car or train is again operated,the operator must leave his control station and go down along the roadbed to the trip valve device which has operated to cause the emergencyapplication of brakes and move the handle thereof back to its normallydepending position to close the vent from the brake pipe, followingwhich, he will return to his control station in the vehicle or train andmove his brake valve device to release position to recharge the brakepipe and brake system for releasing the brakes on the vehicle or trainafter which he may proceed.

Recently new cars placed in the above type of service have been equippedwith what is known as the Smee brake equipment which is substantiallylike that disclosed in the pending application of Samuel L. Williams etal., Serial No. 47,046, filed August 31, 1948, now Patent No. 2,591,224issued April 1, 1952. This brake equipment, in contrast to the Amuebrake equipment, embodies an automatically closing or resetting tripvalve device, that is, a trip valve device which after operation by aroad bed trip to vent the brake pipe for efiecting an emergencyapplication of brakes, automatically closes the vent from the brake pipeto eliminate the need for the operator to leave his control station forresetting the trip valve device, as required with the Amue brakeequipment, to release the application of brakes. Further, with the Smee"brake equipment the operator's brake valve device when in releaseposition does not establish a brake pipe charging communication like thebrake valve device in the Amue brake equipment so that it is notnecessary, when a trip valve emergency application of brakes iseffected, to move the brake valve device out of release position toavoid undesired waste of fluid under pressure. In order to release atrip valve emergency application of brakes with the Smee brake equipmentit is however necessary to move the brake valve device to a full serviceposition for recharging the brake pipe and certain otherparts of theequipment to a certain pressure while retaining the brakes fullyapplied, after which the brake valve device will be returned to releaseposition to release the brakes.

It is now desired to use the automatic closing type of trip valve deviceemployed with the Smee brake equipment on vehicles equipped with the oldAmue brake equipment in place of the manually resettable type which hasbeen used to date but the mere substitution of one for the other willnot be satisfactory since, on account of the brake valve device of theAmue brake equipment establishing a brake pipe charging communication inits release position, an emergency application of brakes initiated byoperation of the automatic closing type of trip valve device could bepromptly released unless the operator promptly moved the brake valvedevice out of its release position which can not be depended upon sincethe operator might be incapacitated.

The principal object of the invention is therefore to so modify the Amuebrake equipment as to permit use of an automatic closing type of tripvalve device therewith.

Other objects and advantages will become apparent from the followingmore detailed description of the invention.

In the accompanying drawings; Figs. 1 and 2, when the right-hand edge ofFig. 1 is matched to the left-hand edge of Fig. 2, is a diagrammaticview, partly in section and partly in outline, of an electropneumaticbrake equipment embodying the invention; and Fig. 3 is a diagrammatic,

emergency application valve device 3 development view of switch andvalve portions 01' two operators brake valve devices shown in Figs. 1and 2.

DESCRIPTION As shown in the drawings, I is a fluid pressure supply pipeadapted to be constantly supplied with fluid under pressure from anysuitable source, such as a reservoir la; 2 is a brake pipe; 3 is anelectric supply wire connected to one terminal of an electric supplysuch as a battery 4, the other terminal of which is grounded at 5; 6 isa brake release wire; I is a service application wire; and 8 is anemergency application wire, all of said pipes and Wires being adapted ito extend to opposite ends of a, vehicle for connection withcorresponding parts on-another vehicle, in the case of a train. 9 is abrake controlling valve device and I and Illa are two identicaloperators brake valve devices adapted to be located at opposite ends ofthe vehicle. II is .a feed valve pipe connected to-brake valve devices I0, I Oa. and adapted to be constantly supplied with fluid fromthe supplypipe I at a suitable reduced pressure through a constant pressure outletor reducing valve device Ila. The parts so farenumerated are identicalin structure and operationand are connected in the same manner ascorresponding parts in the Amue brake equipment disclosedin the abovereferred to Instruction Pamphlet ,andsince reference may be :made tosaidPamphlet ior a detailed description of this equipment, only briefdescription of these partsis necessary for an understanding or" theinvention which description will now be given.

The brake controlling valve device 9 comprises a service applicationvalve device I2 adapted to respond to a service reduction in pressure inthe brake pipe 2 to supply fluid from a precharged auxiliary reservoirI3, at a pressure correspondservice.application valve device I2andemergency application valve device I6 are adapted to operate to theirnormal position for releasing fluid {under pressure from the brakecylinderdevice I5 and for recharging the auxiliary reservoir I3 withfluid under pressure from the brake pipe.

The service application valve device I2 and I6 are mounted on oppositesides of a pipe bracket Ila with which there is associated a magnetvalve portion comprising .a release magnet IB, a service applicationmagnet I9 and an emergency application magnet 20, said magnets beingconnected to the release, service and emergency wires 6, I and 8,respectively. Upon supply of electic current from battery 4 to therelease wire 6 and service wire 1 the release magnet I8 and servicemagnet I9 are adapted to be energized to, respectively, close a ventfrom the brake cylinder device I5 and to supply fluid under pressure tosaid brake cylinder device for efiecting a service application of brakeson thevehicle. Upon energization of the release wire 6 and emergencywire 8 The brake conby current from battery 4 the release magnet I8 andemergency magnet are adapted to be energized for, respectively, closinga vent from the brake cylinder device the same as in effecting a serviceapplication of brakes, and for also supplying fluid under pressure tothe brake cylinder device I5 for efiecting an emergency application ofbrakes. Supply of electric current from battery 4 only to the releasewire '6 subsequent to effecting a service application of brakes willmaintain the vent from the brake cylinder device I5 closed totherebyhold an application of brakes in efiect.

Thflbrake valve devices I0 and Illa each comprises an electric switchportion 22 and a valve portion 23 including a rotary valve 24, saidswitch portion. and rotary valve being arranged for operation in unisonby a common shaft 25 adapted to be turned by an operators removablehandle 26. Only one handle 26 is provided on a vehicleand is applied tothe brake valvedevice at the selected control end of the vehicle,as-shown in the drawmg.

The brake valve handle 26, and thereby the electric portion 22 androtary valve 24 in each brake valve device has spaced apart, Release,Electric Holding, Handle Off, Lap, Service and Emergency positions, asdesignated in Fig. 3 by legends. The brake valve handle26 is shown inFig. 1 in its Release position and in Fig. 2 in its Handle Off position.

The electricportion 22 of each brake valve device I0 and Illa comprisesfour spaced apart-fixed contacts 28, '29, '30 and 3I and a movablecontact 32 (Fig. 3) arranged to cooperate with said fixed contactsaccording to difierent positions of the brake valve handle 26, as willbe presently described. The fixed contact 28 is adapted to be connectedto the current supply wire 3 by a removable plug switch-33 only one ofwhich is provided on the vehicle and adapted to be used at the end ofthe vehicle from which it is desired to control the vehicle brakes. Atthe opposite or non-control end of the vehicle the fixed contact 28 inthe brake valve device will not therefore be connected to the currentsupply wire 3. The contactsZQ, and BI at both brake valve devices I0 andIlla are connected respectively to the release Wire 6, the serviceapplication wire 1 and h em rg a i at o Wire In each brake valve deviceI0, I00, the rotary valve 2. is onta ned m cham er 35 whi h i onst tsupp i d wit flu d und r p ssu from the feed valve pipe II. Each brakeyalve device further comprises anequalizing discharge valve deviceembodying .a piston 36 subject on ne side to pressure of fluid in achamber 37 which ,is connected to a passage .38 leading in one directionto the seat of rotary valve .24 and in the opposite direction to anequalizing reservoir 39. At the opposite side of piston 36 is a chamber40 connected :to .a passa e 4i leading to the seatof rotary valve 24}andalso connected to a brake pipe charging pipe .132 adapted to be normallyopen to brake pipe 2 through a brake application control valve device.43 at the brake valve device I0, .01 a brake application control valvedevice 43a at the brake valve device I Be. The valve devices 43, 43aconstitute a part of the invention and will be described subsequently.Carried by piston 36 is a ,brake pipe discharge valve 44 arranged tocontrol communication between chamber 40, and thereby .the brake pipe 2,and an exhaust passage 45 leading to the seat of the rotary valve 24.

Assuming that the brake valve device Him is at the non-control end ofthe vehicle and in Handle-Off position and that the plug switch 33 isapplied only at the opposite or control end, it will be noted that thecurrent supply via wire 3 to said brake Valve device is cut off and therelease contact 29, service contact 33 and emergency contact 3| aredisconnected from each other, while at the rotary valve 24, passage 4|from the brake pipe 2, passage 45 from the brake pipe discharge valve 44and passage 38 from the equalizing reservoir 39 are all lapped by saidrotary valve, so as to provide for control of brakes only by the brakevalve device I!) at the opposite or selected control end of the vehicle.

With the brake valve device It at the selected control end of thevehicle in Release position, in which it is shown in Fig. 1, a port 45through the rotary valve opens chamber to the brake pipe passage 4i, andassuming that said chamber is charged with fluid under pressure from thesupply pipe I, such fluid will flow through said port to said passageand thence through the brake application valve device 43 to the brakepipe 2 to charge same and to thereby actuate the service applicationvalve device 12 and emergency application valve device E6 of the brakecontrolling valve device 9 to their normal or brake release positions.equalizing piston 36 being connected to the brake pipe passage 4| willalso become charged with fluid at the same pressure as present in thebrake pipe 2.

Fluid under pressure. from the rotary valve chamber 35 in brake valvedevice Ill will also flow through a port 4'! in rotary valve 24 topassage 38 and thence to the equalizing reservoir 39 and equalizingpiston chamber 31 to charge said reservoir and chamber with fluid at thesame pressure as in the brake pipe. With the equalizing piston 35 thussubject on opposite sides to the same pressures of fluid, said pistonwill hold the discharge valve 44 seated.

Also in Release position of the brake valve device Ill no electricalcircuits are established in the electric portion 22 whereby the releasemagnet l8 will be deenergized for venting the brake cylinder device [5.

Now let it be assumed that the handle 26 of the brake valve device In isturned to Service position. The release magnet IE will thereby beenergized to close the brake cylinder release vent and the serviceapplication magnet 19 will also be energized to effect anelectro-pneumatic service application of brakes. The rotary valve 24will also be in service position in which the brake pipe passage 4| andequalizing piston chamber 40 are disconnected from the fluid pressuresupply in rotary valve chamber 35 and connected by way of a cavity 41ato an exhaust passage 48, and at the same time a cavity 49 in the rotaryvalve will connect equalizing reservoir passage 38 to an exhaust passage50 to which the discharge valve passage will also be open via a cavity5! in the rotary valve. The consequent venting of fluid under pressurefrom the equalizing reservoir 39 and piston chamber 3'! will reduce suchpressure below the brake pipe pressure in chamber 49, as a result ofwhich, the equalizing piston 36 will move up to unseat the dischargevalve 44 whereupon fluid under pressure will also be vented from thebrake pipe 2 past said valve to passage 45 and thence through cavity 5!in the rotary valve and exhaust passage .55 to atmosphere. It will benoted that fluid under Chamber 48 below the pressure is vented from thebrake pipe 2 via cavity 41a in the rotary valve as well as past thedischarge valve 44, the vent via cavity 41a initiating the reduction inbrake pipe pressure sooner than would be the case past said dischargevalve, but due to the relatively large volume of the brake pipe 2 on avehicle as compared to that of the equalizing reservoir 39, thereduction in pressure in said reservoir and equalizing piston chamber 37will overtake and then lead the reduction in brake pipe pressure uponopening of the discharge valve 44 to permit the reduction in pressure insaid reservoir to control the degree of reduction in pressure in thebrake pipe 2, as will be later brought out.

If the service magnet It becomes energized and effects an application ofbrakes as intended upon movement of the brake valve handle 26 to serviceposition, the reduction in pressure in brake pipe 2 effected as justdescribed will be to no avail, but in case such an application of brakesfails to materialize, then the service portion I2 of the brakecontrolling valve device 9 will operate in response to the reduction inpressure in brake pipe 2 to effect an application of brakes.

When a desired degree of service brake application is obtained the brakevalve handle 26 will be moved to Lap position to efi'ect deenergizationof the service application magnet l9- while holding the release magneti3 energized. The supply of fluid to the brake cylinder device I5 willthereby be cut oflf while the release magnet remaining energized willhold the pressure in said brake cylinder device to maintain the brakesapplied.

Also in Lap position of handle 26 the brake pipe 2 will be disconnectedfrom the exhaust passage 48, the equalizing reservoir 39 will bedisconnected from the exhaust passage 50 but the brake pipe dischargevalve passage 45 will remain open to the exhaust passage 59 viacavity-50a. The reduction in pressure in the equalizing reser- -voir 39and piston chamber 3! Will thereby be terminated, but brake pipepressure acting on the opposite side of the equalizing piston 36 willhold the discharge valve 44 open and permit fluid under pressure tocontinue to release from the brake pipe 2 until the pressure thereinbecomes reduced to substantially that still effective in equalizingpiston chamber 3'! whereupon the piston 36 will be operated to seat thedischarge valve 44. If the. application of brakes is due to thereduction in pressure thus effected in the brake pipe, the degree ofsuch application will be correspondingly limited by operation of theservice application valve device l2 in the well-known manner.

If it is desired to effect an increased application of brakes, the brakevalve handle 26 may be moved from Lap position again to Service positionto increase the application to the desired degree, and then be movedback to Lap tposition as will be clear from the above descrip- If due toenergization of the release magnet l8 and service magnet I9 the brakeson the vehicle are applied and it is desired to restore the pressure inbrake pipe 2 back to normal while holding the brakes thus applied, thebrake valve handle 23 will be moved to Holding position in which therelease magnet I 8 will remain energized to hold the brakes applied, andin which via ports 46 and 4'! in the rotary valve 24 the brake pipe 2and equalizing reservoir 39 and thereby chamhers 31 and in "to oppositesides 'of'theequali'zin'g piston 36 will 'be recharged with fluid to thepressure normally'carried in the brake-pipe. -It will be apparent thatif "the application of brakes were 1 due to the previous reduction in-p'res'sur'e in brake pipe-2, the recharging of the brake pipe inHolding position would release such applicationft'hat is, the Holdingposition is only-for the purpose above described and is of no acco'untwhen the application is due to a reduction in pressure in brake pipe2. V

In'order=to-release *an application of brakes, the brake valve handlewill be returned to Release? position fordeenergizing the release magnetl8 an'd'ior recharging the brake pipe2 in*'the-same manner as-in Holdingposition, if not already so charged, whereupon the release of brakeswilloccur due either to operation'of-s'aid magnet or the increase inpressure in the brake pipe, as the case may be.

'If it is desired to effect an emergency application of'brakes the brakevalve'handle 26 will be moved to "Emergency position for energizingthe'release magnet 18 and emergency magnet 20 and'for at the same timeopening the brake pipe passage 4| to the exhaust passage 53 via cavity52in the rotary valve "24 whereby, in either case, an emergencyreduction in brake pipe pressure will 'occur to cause operation of theemergency portionlB of the brake ontrolling valve device '9 toefiect'an-emergency application of brakes on the vehicle.

In"o'rclerto release the brakes after an emergencyapplica-tion, thebrake-valve handle'25 may be "returned 'to Release position, or first toHolding" position, if desired, whereupon the release will occur in thesamemanneras above described.

Ihe brake application control valve devices 43, 43a are identical, eachcomprising two spaced apart-and coaxially arranged pistons56, 5'!connected-together by a stem 58. The two pistons 55, 5! cooperate toform between them achamb'eri59 'open to-the respective brake pipecharging pipe 12; =while at the opposite side of piston 57 thereisa-brake application control cha-mber'fill open .to the feed valve pipeI'I through a restriction :or choke iii whereby there is adapted to be aconstant reduced flow of fluid under pressure to chamber from said pipe.Disposed in a cavity .inlthe outer face of piston 56 is a valve'62arranged :to -I1o0perate with -an annular seat =rib fi3:inthe .casing tocontrol communication between an atmospheric passage 64 encircled bysaid rib and an annular cavity :encircling said rib. A shoulder 56projecting-from ,piston55 is arranged to contact valve 62 to pul1 samefrom its seat on rib 63 upon movement of said piston away-from saidseat. A spring 6'! resiliently urges the valve 82 toward shoulder 55.

With the valve 62 engaging seat rib 63the piston 56 .is adapted to opento chamber 59 'a-pluralityof ports 58 which are connected bya pipe 69 tothe brake pipe 2. The pistons 56, 51 are adapted to move from theirnormal position, in which they are shown in the drawing, toa brake pipeventing position defined by sealing engagement of a rib T0 in the outerface of ,piston 51 with a gasket -'H. In this venting position the valve62 is adapted to be unseated and the piston 56 disposed at .the side ofports 68 opposite that in which it is shown in the drawing to therebyclose communication between chamber 59 and the pipe 69 and to open saidpipe to the atmospheric passage 64. In the normal position of piston51-an annular'rib IZ on its inner face is adapted to seal against agasket 13, the sealing of the ribs 10 and-'12 with-"therespectivegaskets -'H and 13being ad'a'ptedto preventleakage of fluidun'derpressurefrom chamber'60'to chamber 59 in the different positionsof piston "51. A spring H 'cont'aine'd in chamber Bil'acts onthe piston56 for urging said piston and the piston 57 to their normal position.

Each brake application control valve device 43, 43a further comprises alockjv'alve 14 con-- tained ina chamber '75 for'coritrolling'commu'nicat-ionbetween said chamber and the brakeapplicati'on control chamber-60 through a bore in Which'there issli'dabl'ymounted a 'fluted stem 16 of said valve. A spring 18 acts onthe valve {'14 for urging it toward its seat. The valve 14 and its-"stem16 are arranged in coaxial-relation to the piston 57, and said stemextends into'th'e brake application control chamber 69 for engagement bya projection I9 from piston 56 to unseat said valve upon movement of thepistons 56, 57 to open the -'valve'62. With the valve '62 seated theprojection 79 is adapted to be spaced from valve 74 to'ensure seating ofthe latter valve by spring 18. In each brake application control valvedevice 63,430; the lock valve chamber '75 is connected by a lock controlpipe 81 -to-'a passage 82 mare respective brake valve device [0, lOaand, according to the invention, toa volume chamber 8i forreasons whichwill become obvious hereinafter. The passage- 82 ine'ach brake valvedevice Hi, lea constitutes a passage already present but not now used inthe brake valve devices of the Amue brake equipment and the rotary valve24 of said brake valvedevice is also provided with passages 83, '84 forconnecting'passage 82 to the exhaust passage 50 in, respectively, theRelease and Handle Off positions of said rotary valve, said rotary valvelapping passage in all other positions of said rotary valve. Alsoaccording to a feature of theinvention, the chamber 66 in each brakeapplication control valve device 43, 131; is'conne'cted by a brakeapplication control pipe'fifl anda conduit 104 to a respective'automaticclosing trip valve device 1 03, l03a, one at each 'endof the vehicle.The brake pipe 2 has a connection withthe respective brake applicationcontrol pipe at each end of the vehicle'by'wa'y of a respective springbiase'd'check valve device H0 which will allow 'fiow'of fluid from thebrake'pipe 2'to'the control pipe 80 upon establishment of a certainpreponderance in pressure in the former'pipe over'that in the latter andwill prevent flow of fiui'd inthe reverse direction.

Th'e'trip valve devices Hi3, l03a are identical'to those employed in theSince brake equipment heretofore referred to, each trip valve devicecomprising a normally depending arm i0 5 adapted upon engagement with aroad bed trip (not shown) to be swung outof its depending position toopen the conduit I04, hence control pipe 80, to atmo'sphere,-and whichis adapted to automatically return to its depending position and closecommunication between brake application control pipe 8!} and atmospherewhen pressure of fluid in the control pipe is reduced to a chosen lowdegree.

Each of the spring-loaded check valve devices, for sake of illustration,may comprise a casing HI having a chamber H2 therein open to theexterior of the casing at-an inlet I I3 and an outlet -I M. The inlet IH! is connected to a branch of the brake pipe 2 and the outlet I I4 isconnected to a branch of the pipe 80. Provided in the chamber I52 is aball check valve I I5 which is urged by a compression spring IIB towarda seated position in which it is shown in the drawing for closing thechamber II2, hence pipe 89, to the brake pipe Upon a certainpreponderance in pressure in the brake pipe 2 over that in the brakeapplication control pipe 89, to be described hereinafter, the action ofthe spring H6 will be overcome and the ball check valve will unseat;opening the brake control pipe 2 to the ipe 33 via the chamber II2.

OPERATION In operation, let it be assumed that the handle 26 of thecontrolling brake valve device II] is in Release position in which it isshown in Fig. 1, that the other brake valve device its is in Handle onposition in which it is shown in Fig. 2, and that the brake pipe 2 ischarged with fluid under pressure (in a manner which later will bedescribed) along with the feed valve pipe II, and that the brakes on thevehicle are released.

Supply of fluid under pressure from the feed valve pipe I I will buildup a fluid pressure in chamber 35 in the controlling brake valve deviceI5 and flowing via choke M from pipe II will build up pressure of fluidin the brake application control chamber 58 in each of the brakeapplication control valve devices 43 and 43a equal to that pressure offluid supplied to the respective chamber 59 in device 43 by way of brakepipe charging pipe 42, and in the controlling brake valve device IQ,passage 4 I, ort 46 and the chamber 35 which is charged with fluid underpressure from feed valve pipe It as previously mentioned. As will beappreciated from previous description,

with equalization of pressure of fluid in chambers 59 and 60 in brakeapplication control valve device 43, the respective pistons 56, 5'! willbe caused to assume their normal positions, in which they are shown inthe drawing, by action of'the spring I1 for opening communicationbetween the brake pipe 2 and chamber 59.

In the brake application control valve device 430, the chamber 59 isdisconnected from the feed valve pipe II via pipe 52a and passage M inthe brake valve device Iiia by the respective rotary valve 24, in itsHandle Off position, which blanks oii passage 45. Pressure of fluidsupplied from feed valve pi e Ii to the respective brake applicationcontrol chamber 69 in the brake valve device Ida, being equal to orgreater titan the pressure in respective chamber 59 will therefore allowspring I? to so position pistons 56, 51 as to connect chamber 59 to thebrake pipe 2.

From the feed valve pipe i i, fluid under pressure will flow, in thecontrolling brake valve device IIl, from the rotary valve chamber 35,through port 553, registering passage M, the brake pipe charging pipe42, the chamber 59 in the brake application valve device 43 and pipe 69into the brake pipe 2 to charge same.

Chamber I5 in the brake application valve device 43, and the respectivevolume chamber 8| will be vented to atmosphere at this time by way ofpipe BI, and, in the controlling brake valve II], the passage 82, port33 in rotary valve 2 1 and the passage 58. In the brake applicationcontrol valve device 43a, the corresponding chamber I5 will be closedfrom the atmosphere by the rotary valve 24 in the brake control valvedevice Ifia in Handle Off position.

Assume the trip valve devices I03, 13a to be in their respective closedpositions so that with both the brake application control chamber 60 indevice 43 and the brake pipe 2 charged to the same and feed valve pipepressure, fluid pressure forces across the check valve H5 will be equaland such valve will be seated by the spring I I6, closing off the brakeapplication control pipe 86 from the brake pipe 2.

With chamber 59 in the brake application control valve device 43 or 43aat the control end of the vehicle thus open to brake pipe 2, the brakeson the vehicle may be controlled by operation of the respective brakevalve device I0 or Ilia in the same manner as before described.

With the brakes on the vehicle released, under control of the brakevalve device I6 and the vehicle in motion, let it be assumed that thearm I06 of the trip valve device I03 is struck by a track trip and swungout of its normal depending position to freely vent the pipe I94,connected brake application control pipe 80, and hence the brakeapplication control chamber 69 in the brake application control valvedevice 43 to atmosphere.

With the brake application control pipe thus freely vented to atmosphereby way of the trip valve device 33, fluid under pressure will flow fromthe brake application control chamber 66 of the brake applicationcontrol valve device 43 at a rate which so exceeds the rate of supply offluid under pressure from feed valve pipe II via choked communication GIas'to reduce the pressure sufficiently below the opposing brake pipepressure in chamber 59 that a differential in the opposing fluidpressures on piston 51 will be obtained which will move said piston 56against spring I! to the position defined by contact between the pistonrib Ill and gasket II. This operation of the brake application controlvalve device 43 will close the respective communication between thebrake pipe 2 and the respective chamber 59 and open said brake pipe toatmosphere past the open valve 62 therein to effect an emergencyreduction in brake pipe pressure.

With the non-controlling brake valve device Illa in Handle OIT positionlapping oif the respective communication between the feed valve pipe -IIand chamber 59 in the brake application valve 43a at the time of theclosing of the communication between the brake pipe 2 and chamber 59 inthe application control valve device 43, further supply of fluid underpressure is cut off to the brake pipe from pipe 42 via the brake valvedevice II! which is still in Release position, whereby fluid underpressure will not be supplied to the brake pipe to release the emergencybrake application resultant from the emergency reduction in brake pipepressure after automatic closing of the trip valve device I03.

If, for any reason, venting of the brake application control chamber 60in the device 43 via the trip valve device I03 should fail to eifectventing of the brake'pipe 2, that is, should the piston 5! fail torespond to the reduction in pressure in said chamber 6!), thepreponderance in pressure in the brake pipe 2 over that in the brakeapplication control pipe 80 will cause unseating of the spring loadedcheck valve H5 and venting of fluid under pressure from the brake pipewill occur via brake application'control pipe 80 and the trip valvedevice I03 at a rate greater than it is supplied to the brake pipe fromthe feed valve pipe II via brake control 11 valve device Ill, brake pipecharging pipe 42, and chamber 59 in device 43. .such venting of fluidunder pressure irom the brake pipe will cause an emergency reductioninbrake pipe pres- .sure and a consequent emergency application of thebrakes on the vehicle. Under such conditions, however, if the brakevalve device .lil .is allowed to remain in Release position, when thetrip valve device 103 automatically closes, the fluid-underpressure-supplied from the feedzvalve pipe 1| to the brake pipe 2 willrecharge the .brake pipe and cause release of the brakes. .-I-Iwever,such unintentional release of the brakes may be prevented by movement ofthe brake valve handle 26 to Let Position to 'cut oif supply offluid-under pressure from the :feed valve pipe H :to the brake pipe viabrake pipe charging pipe -42, or to either Service or Emergency positionto likewise cut off such supply and simultaneously also vent :the brakepipe to atmosphere via passage 48 or 50, respectively.

With normaloperation of theiapplication valve device '43., resultantlocal venting .of the brake pipe ,2 by way of the respective atmosphericpassage 64 in said device will preclude -.establishmentof apreponderance in ibrake pipe pressure over that in the respective brakeapplication control ;pipe -80 vented via the -.tr.ip valve device .103sufiicient to unseat the respective spring loaded check valve H5, sothat the check valve 1 l will remain seated during such =0peration.

The operation of the brake application control valve device :43, in:response to emergency operation of .the trip valve device 403 will alsounseat the respective lock valve 14, thereby i opening the respectivebrake :application control chamber 6D to passage 82 :in "the connectedbrake valve device H3. The controlling ebrake valveidevice IU, :being inRelease position opens passage 82 ito'atmosphere via passage 50 so thatthe ;re- .spective :brake application control chamber 269 in the brakeapplication control valve device :43 will thereby -be so vented,allowing any fluid aunder pressure supplied :to the respective cham-:ber :60 from the feed valve pipe l l via respective restrictedcommunication $6.1 'to vent to atmosphere, thereby assuring that :feedvalve pressure in the respective chamber 59 will hold the respectivepiston 51 in the position in which the brake :pipe 2 remains vented viarespective :atmospheric passage .64.

.At the :non-control brake 'valve device 120a its Handle on position,the respective passage 82, hence the respective ?b1ake applicationcontrol chamber 60 in device 43a, is closed to atmosphere by a plug 85in the respective rotary valve passage '84, so that :feed 'vailvepressure in .said chamber 60 will be maintained and the respectivepiston 59 held so ipositioned that :the

'brake pipe 2 will be closed 101T from the respective atmospheric:passage -164 :and connected to the :respective chamber '59, pipe :42,:and passage 4| :in device Illa whichpassage is :closed thereinbytherespectiverotary valve'24.

So long .as the controlling brake valve device remain-sin its Release:position with the ,noncontrolling "brake valve device 1011 in itsHandle Off "position, feed valve supply 'will .be cut off from the brakepipe 2 which will remain vented by way of the unseated valve 62 in theapplica- "tion control valve device 43 and the emergency application ofbrakes on the vehic'lewillbemaintained. Subsequent automatic closure of"the trip valve device I03 will close Off the .brake 'applicationcontrol pipe :80 {fITOlllVGIlbil'IgitO atmos- ,fphere via said tripvalve device, but (the venting of the brake application control chamber0 via the unseated lock valve 14 in device 43 will maintain said chamberso vented via device in in its Release position.

With the brake pipe 2 vented due to operation 'of the trip valve deviceI03 and the brakes .on the vehicle appliedas a result, and with thecontrolling brake valve device J0 still in Release position it will benoted that there will .be a continuous undesired leak of fluid underpressure from the brake system to atmosphere through choke 16! and pastthe open lock valve 14 in the brake application control valve device 43and thence through said brake valve device.

In order -to stop such loss of fluid under pressure, the handle 126 ofthe controlling brake valve device I0 may be moved to Lap position toclose communication to passage .82 and to also cut off the supply-offluid under pressure to passage 4i and chamber 59 in the brakeapplication control valve device 43. With passage '82 .in the brakevalve idevice 1.0 thus lapped, ifiuid .under pressure suppliedthroughchoke 6| to the brake application control chamber 60 in the brakeapplication control valve device 23 and via lock control pipe 8| tovolume chamber .ill' will build .up the pressure therein eventually .tothat present in the feed valve pipe .LI, and when sufiicientlyincreased, spring 11 will return the parts .of said brake applicationvalve .device to their normal position .for closing the brake .pipe ventvalve 52, opening communication between the .connected brake pipecharging pipe 42 .and the brake pipe .2 and permitting closure of thelock valve 14, but with the .brake valve device in Lap position therewill beno supply of .fluid under pressure to said brake pipe chargingpipe 42 and the brake pipe 2.

As will be appreciated from subsequent description, the volume chamber.81 so delays build up of pressure in the brake application con- .trolchamber 60 that sufficient time elapses for an emergency application ofthe brakes to have stopped the vehicle before the piston 51 in device'43 is returned to normal :position to connect the brake pipe 2 to thebreak pipe charging pipe 42 and thereby establish a communicationthrough which the brake pipe may .be recharged to release the brakes.

At the non-control end of the vehicle, the parts of the brakeapplication control valve device 43a will remain in their normalpositions following the trip valve emergency application of brakes, asbefore mentioned, maintaining the brake pipe 2 connected to the brakecontrol valve device 10a in its Handle Ofi position and thereby cut-oilfrom feed valve supplypipe ll.

With return of the application control valve device 43 to its normal'position and consequent establishment of the connection between thebrake-pipe 2 and the brake valve device In via brake pipe charging pipe42, the brakes on the vehicle will remain applied so long as said brakedevice -10 remains in its Lap position cutting off said brake pipecharging pipe 42, hence brake pipe '2, from feed valve supply pipe l'l.

Whenever the operator desires to release the application of brakeseffected by operation 'of the trip valve device fl3, he will turn handle'26 of the controlling brake valve device it 'from Lap' position toRelease position in which fluid undcr'pressure will again be supplied tothe connected brake pipe charging pipe '12 'from which 'it will :flowthrough the brake application control valve device 113 to the brake pipefor recharging same and thereby effecting operation of the brakecontrolling valve device 9 to release the vehicle brakes. The fluidunder pressure thus supplied to the brake pipe at the control end of thevehicle will flow to the non-control end and through ports 68 to chamber59 in the brake application control valve device 43a but will have noeffect thereon since the opposite side of the respective piston 51 isalready subject in the brake application control chamber 39 to fluidpressure from the feed valve pipe ll.

Since the brake valve device 10, 10a, and other parts of the brakeequipment at the two ends of the vehicle are identical, the operation ofthe equipment in response to operation of the trip valve device [93awhen the control end of the vehicle is at brake valve device ma will bethe same as above described when the brake valve device 19 was thecontrol brake valve device, as it is believed will be evident.

SUMMARY From the above description it will be seen now that by theaddition and arrangement of the brake application control valve devices43, 43a, the volume chambers 8!, and the check valve devices H9 to theAmue brake equipment, as above described, the automatic closing tripvalve devices I03, 193a may be used in connection with said equipmentsince the supply of fluid under pressure to the brake pipe will be cutoff by one or the other of said brake application valve devices inresponse to operation of a respective trip valve device, therebyassuring that the brakes on the vehicle will apply and not beundesirably released upon automatic closure of said trip valve device.With these additions to the Amue equipment, the plug 85 in the rotaryvalve of the brake valve devices is necessary in order to prevent fluidunder pressure supplied to the brake pipe by the controlling brake valvedevice from dissipating to atmosphere by way of the non-controllingbrake valve device in its Handle Off position.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a fluid pressure brake equipment, in combination, a source offluid under pressure, a brake pipe, a feed valve pipe constantly availedof fluid under pressure from said source, a brake pipe charging pipe, abrake application control pipe, a lock control pipe, an operators brakevalve device having a release position for establishing a fluid pressuresupply communication between said brake pipe charging pipe and said feedvalve pipe and an exhaust communication between said lock control pipeand atmosphere and having a lap position for closing both said supplycommunication and said exhaust communication, a brake applicationcontrol valve device having one chamber in restricted communication withsaid feed valve pipe and unrestricted communication with said brakeapplication control pipe and having a second chamber connected to saidbrake pipe charging pipe, said brake application control valve devicebeing operable upon substantial equalization of pressure in said onechamber with pressure in said second chamber to a brake release positionfor opening said brake pipe to said brake pipe charging pipe and beingoperable upon a reduction in pressure in said one chamber relative tothat in said second chamber to a brake application position for openinga vent from said brake pipe to atmosphere and for also opening said onechamber to said lock control pipe, and automatically closing road bedoperable trip valve means for venting said brake application controlpipe to atmosphere.

2. The combination as set forth in claim 1, including a volume reservoirconnected to said lock control pipe to delay build up of pressure insaid one chamber from restricted flow of fluid under pressure from saidfeed valve pipe when said brake application control valve device is inits brake application position, said trip valve device is closed, andsaid brake valve device is in its lap position closing off said lockcontrol pipe from the atmosphere.

3. The combination as set forth in claim 1, including spring loadedcheck valve means having an inlet connected to said brake pipe and anoutlet connected to said brake application control pipe to allow forrelease of fluid under pressure from said brake pipe in response toestablishment of a certain differential in pressure between said brakepipe and said brake application control pipe resultant from operation ofsaid trip valve means and failure of operation of said brake applicationcontrol valve device.

EVERETT P. SEXTON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,104,823 Murphy July 28, 1914 1,129,319 Turner Feb. 23, 19151,130,447 Turner Mar. 2, 1915 1,192,331 Lewis July 25, 1916 1,538,932Farmer May 26, 1925 1,694,193 Sproull Dec. 4, 1928 1,855,595 BushnellApr. 26, 1932

